the doctor. "Where should I be?"

"You would be under lock and key, my friend," said Beale.

The doctor threw back his head and laughed softly.

"What a lover!" he said, "and how reluctant to accept his dismissal! It
may ease your mind to know that Miss Cresswell, whom I hope very soon to
call Mrs. van Heerden, is perfectly happy, and is very annoyed at your
persistence. I had a telegram from her this morning, begging me to come
to Liverpool at the earliest opportunity."

"That's a lie," said Beale quietly, "but one lie more or less, I
suppose, doesn't count."

"A thoroughly immoral view to take," said the doctor with much severity,
"but I see there is nothing to be gained by arguing with you, and I can
only make one request."

Beale said nothing but stood waiting.

"It is this," said the doctor, choosing his words with great care: "that
you call off the gentleman who has been dogging my footsteps to-day. It
was amusing at first but now it is becoming annoying. Some of my
patients have complained of this man watching their houses."

"You've not seen a patient to-day, van Heerden," said Beale, "and,
anyway, I guess you had better get used to being shadowed. It isn't your
first experience."

The doctor looked at him under lowered lids and smiled again.

"I could save your man a great deal of trouble," he said, "and myself
considerable exertion by giving him a list of the places where I intend
calling."

"He will find that out for himself," said Beale.

"I wish him greater success than he has had," replied the other, and
passed on, descending the stairs slowly.

Beale went back to his flat, passed to his bedroom and looked down into
the street. He made a signal to a man at the corner and received an
almost imperceptible answer. Then he returned to the two men.

"This fellow is too clever for us, I am afraid, and London with its
tubes, its underground stations and taxi-cabs is a pretty difficult
proposition."

"I suppose your man lost him in the tube," said McNorton.

"There are two ways down, the elevator and the stairs, and it is mighty
difficult to follow a man unless you know which way he is going."

"But you were interrupted at an interesting moment. What are you going
to tell us about the Green Rust?"

"I can only tell you this," said Beale, "that the Green Rust is the
greatest conspiracy against the civilized world that has ever been
hatched."

He looked sharply at Homo.

"Don't look at me,"